Abstract 3409
Background
Immune checkpoint inhibitors (ICPi) have dramatically changed the treatment of non-small cell lung cancer (NSCLC), but the effect of these agents on brain metastases (BM) has not been clearly elucidated. We retrospectively evaluated the effect of ICPi on BM.
Methods
NSCLC patients who harbored BM treated with ICPi in out institution were enrolled. History of radiation therapy (RT) to the brain was not included in the selection criteria. The primary endpoint was overall survival after the initiation of ICPi (OS), and the secondary endpoints were duration of ICPi administration, causes of withdrawal, responses of BM, time to the first response of BM, and the incidence of radiation necrosis (RN).
Results
35 NSLC with BM were treated with ICPi: nivolmab in 21, pembrolizumab in 13, and athezolizumab in 1 case. Among these cases, BM were progressive in 25 but stable in 10 cases at the initiation of ICPi. At the time of evaluation, ICPi were already withdrawn in 26 cases and the median administration time was 2.4 (0.5 to 25.9) months. The cause of withdrawal was progression of extracranial lesions in 8, progression of BM in 6, and adverse events or PS deterioration in the others. In competing risk analysis, the times to progression of extra- and intra-cranial lesions were not different. The responses of BM were evaluable in 28 cases: CR in 3, PR in 9, SD in 10 and PD in 6 cases. ICPi had been sequentially administrated after RT in one of the 3 CR and all of the 9 PR cases. The objective response rate was 76.9% after sequential RT/ICPi, but only 13.3% after ICPi alone (P = 0.002). The median time to the first response of BM was 1.0 (0.4 to 3.0) months after RT/ICPi and 1.3 (0.3 to 3.6) months after ICPi alone (n.s.). The median OS was 14.8 (95% CI: 8.8 to 22.7) months after the initiation of ICPi, and majority (90.5%) of the deaths were owing to the progression of extracranial disease. Among the 24 cases with history of RT to the brain, RN was observed in 7 (29.2%) and required necrotomy in 2 cases, even though ICPi could safely be continued after craniotomy in these 2 cases.
Conclusions
ICPi alone showed only limited efficacy on BM and were recommended to be administrated sequentially with RT. RN was the major neurological adverse event, and necrotomy was one of the choices to manage RN during ICPi.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
2182 - Evaluating the prevalence of the expression of PD-L1 in NSCLC specimens with short-duration formalin fixation using IHC 22C3 pharmDx
Presenter: Keiichi Ota
Session: Poster Display session 1
Resources:
Abstract
5255 - [18F]-FDG PET/CT in predicting PD-L1 status in nasopharyngeal carcinoma
Presenter: Liang Zhao
Session: Poster Display session 1
Resources:
Abstract
4910 - Expression of PD-L1 in Chinese Patients with Common Cancers
Presenter: Min Zheng
Session: Poster Display session 1
Resources:
Abstract
4227 - The clearance of EGF by tumor-associated macrophages is suppressed by chemotherapeutic agent cisplatin
Presenter: Irina Larionova
Session: Poster Display session 1
Resources:
Abstract
5222 - VHIO-300 and a thousand one nights, a tale of Precision Medicine
Presenter: Ginevra Caratù
Session: Poster Display session 1
Resources:
Abstract
5668 - Matched Whole-Genome Sequencing and Whole-Exome Sequencing with Circulating Tumor DNA (ctDNA) Analysis are complementary modalities in clinical practice
Presenter: Robin Imperial
Session: Poster Display session 1
Resources:
Abstract
5772 - Exploring the role of genes associated with familial cancer syndromes on the development of multiple primary tumors
Presenter: Atanaska Mitkova
Session: Poster Display session 1
Resources:
Abstract
4784 - Doxorubicin resistance: early and advanced tumors can use two different strategies based on initial and profound abnormalities in microRNA expression signature
Presenter: Volodymyr Halytskiy
Session: Poster Display session 1
Resources:
Abstract
3456 - From tumor transcriptomes to underlying cell type proportions to better predict prognosis and response to treatments
Presenter: Yuna Blum
Session: Poster Display session 1
Resources:
Abstract
4976 - Optimization of automated germline DNA extraction from non-tumoral formalin-fixed paraffin embedded (FFPE) tissues
Presenter: Omar Youssef
Session: Poster Display session 1
Resources:
Abstract